Patent GB-191316353-A (GB)
Title: Improvements in and relating to Colour Kinematography.
Inventor: MIDDLETON THOMAS PERCY
IPC: G03B27/475
Filed: 1913-07-16
Granted: 1914-07-16
Abstract: 16,353. Middleton, T. P. July 16. Enlarging, copying, &c.-Lens copying-apparatus is described for the production from motion-picture film negatives containing a recurring series of, say, red, green, and blue images, of separate component positive films of each of the colour series. The apparatus comprises two synchronized kinematograph movements in which the gearing for controlling the periodic selection from the negative band can be adjusted, (1) for single reproductions of the periodically selected image, as is required when each successive sets of colour images in the negatives are exposed simultaneously and the negative band fed with a multiple shift at normal speed; or, alternatively, (2) for repeating the periodically selected image on the positive band, as is required when the negative band is exposed at normal speed through recurring filters, or at one-third the normal speed in sets and through stationary coloured filters. To avoid any fringing in the superposed positives, five sprocket holes are allowed per picture in the negative band, so that, by means of the masking gate of the copying-apparatus and by the adjustment of the lens, any particular part of the negative images can be selected, and the corresponding parts of each image accurately superimposed on the positive film. The same positive band may be re-sensitized and the successive series copied in superposition. The three images may be superimposed on the same side of the band, or two of the components may be on opposite sides. In the latter case, the second image is obtained by using a lightfilter of the same colour as the positive already on the film in order to neutralize the effect of this already printed positive in copying through the film. The copying-lens, Fig. 1<a>, is adjustable vertically and horizontally by means of slides 5, 6 and adjusting-screws 13, 18. The two kinematograph mechanisms are synchronized by being driven from a common shaft 140, Fig. 4, in gear with pinions 137, 135 on the feed-shafts 80, 20 of the negative and positive mechanisms respectively. In the positive mechanism, the shaft 20, Fig. 2, carries the pin-wheel 27 of the Maltese-cross feed shown in Fig. 8. The driven shaft 30 carries the intermittent sprocket 35. The delivery and take-up sprockets 40, 34 and the take-up spool 141 are driven through connected gearing from the feed-shaft 20. In order to keep the film stationary in the gate during an exposure, a bar 58 carrying pins to engage the sprocket holes while the film is in the gate is intermittently reciprocated by means of a cam-disk 25, Fig. 2, on the pin-wheel shaft, a roller 65 rolling thereon and thereby oscillating the spring-controlled shaft 63, Figs. 1<a> and 4, and the arm 62 which is directly in engagement with two parallel face-plates on the bar 58. The shutter 76, Fig. 1<a>, is also driven from the feedshaft 20 through gearing 69, 70, 71, 72. In the negative mechanisms, the feed-shaft 80, Fig. 3, carries the pin-wheel 87 of the feed-mechanism which is arranged to give a three-picture .shift. The shaft 80 is also movable towards and away from the feed-cross 92 on the intermittent sprocket shaft 91 and carries an additional circular flange 88. The shaft is pressed towards the position of normal engagement with the cross 92 by the bowed spring 115 at the end 80<b>. As in the case of the positive mechanism, the delivery and take-up sprockets 97, 107 and the take-up spool are driven by connected gearing from the feed-shaft 80. The speed of these sprockets is, however, different according to the position of the shaft 80 that drives the take - up shaft 106 either through gearing 133, 134 for case (1) above or through slow gearing 82, 109 for case (2). The gear 82 is sufficiently wide to be permanently in engagement with a gear-wheel 83, Fig. 7, on a parallel shaft 84, carrying a cam-surface 110 on its face. An adjustable roller 112 secured to a parallel sliding bar 113 rotates in contact with this cam 110, and any motion of this bar due to the engagement by the cam 110 and roller 112 is transmitted to the shaft 80 through a pivoted bar 114, connected to the bar 113 and the other end of which presses on the end 80<a> of the shaft 80 opposite to that engaged by the spring 115. For case (1) above, in which a triple-shift feed at the same speed on the negative film is required, the roller 112 is removed from the bar 113, the gears 133, 134 are connected, and the pin-and-cross mechanism is in normal engagement. For case (2), in which each negative image is repeated three times, the roller 112 is positioned on the bar 113 so that, by virtue of the engagement with the cam 110, the shaft 80 is moved during two out of every three revolutions against the action of the spring 115, taking the pin-wheel out of the path of the cross 92, but on the third revolution, the cam allows the spring 115 to move the pin - wheel into the feed position and thereby effect a feed during each third rotation. With this feed, the slow gears 82, 109 are in engagement. Steadying-pins 121, to engage the sprocket holes of the negative periodically during printing and similar to the steadying-pins 85 for the positive film, are reciprocated by similar oscillating bars 125 on a shaft 126, which is oscillated from the shaft 80. For the normal feed, the roller 129 on an arm 127 of the shaft 126 rides on the cam-surface 86 of the wheel 85 on the shaft 80. To prevent the retraction of the pins at each revolution of the shaft when the feed is only effected at each third revolution, the wheel 85 carries an adjacent circular surface which comes into engagement with the roller 127 when the shaft 80 is shifted laterally.